Process for refining silver bullion.



BALMER NEILLY, OF BRADFORD, ONTARIO, CANADA.

PROCESS FOR REFIN'ING SILVER BULLION.

No Drawing.

Specification of Letters Patent.

Application filed December 31, 1909.

Patented Oct. 3, 1911.

Serial No. 535,731.

To all whom it may concern:

Be it known that I, BALMER NEILLY, of the town of Bradford, in the county of Simcoe, in the Province of Ontario, Canada, have invented certain new and useful Improvements in Improved Processes for Itefining Silver Bullion, of which the following is the specification.

My invention relates to an improved process for refining silver bullion and the object of the invention is to provide a process in which the loss will be exceedingly low and the cost of refining small.

The apparatus I now use for carrying out the above process comprises a suitable furnace and means for supplying a blast of air to the surface of the molten metal contained in the furnace.

In order to get rid of nickel copper or cobalt present along with as much arsenic and antimony as possible I form what is termed a speiss. In order to do this the bullion is melted down in the cyclone furnace at about a temperature of 11 10 C. and iron in the form of nails added until the iron is attacked by the arsenic and antimony present. The crucible is then removed and cooled suddenly. Under these conditions the speiss separates cleanly from the bullion. The bullion is again melted down at a temperature of about 1090 C. with enough flux such as sand and borax to form a thin covering on the top of the molten metal. Air With sufficient pressure to cause a depression of about 9; of an inch on the surface is then blown on the metal until the arsenic first and then antimony are oxidized off leaving the bullion pure. This point of course is easily determined. Samples are dipped out and after cooling hammered. If they are inclined to be brittle to the least degree the metal still retains some impurities. Even a small fraction of one per cent. impurities will cause it to crack. Again on becoming pure the molten metal changes from white to a clear sea green in color.

The above process it will be seen is accomplished with a very simple apparatus and is cheap and quick.

What I claim as my invention is:

The process for refining silver bullion consisting in first melting the bullion and adding to the fused metal iron to form a speiss then suddenly cooling the metal to separate the bullion from the speiss then remelting the bullion and covering the surface of the melted bullion with a flux of a mixture of sand and boraX and finally subjecting the surface of the flux to a blast of air, as and for the purpose specified.

BALMER NEILLY.

Witnesses:

R. GOBAIN, B. Born.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

